This project proposes a series of experiments that will contribute to the burgeoning field of the neuroeconomics of aging, which attempts understand the component processes of decision-making across the lifespan by examining both behavior and the underlying neural substrates. The proposed studies seek to begin specifying the mechanisms of decisions, in particular the deliberative and affective components that make up the decision-making process. Affective influences on decision-making have been largely ignored for many years, but recent interest in how our emotional states can affect the type of decisions we make offer an exciting opportunity to broaden our knowledge of this most important process. Further, examining the degree to which affective and deliberative processing differentially influence decision-making across the lifespan can provide important clues for the assessment of these basic cognitive functions. Specifically, the proposed experiments will use functional magnetic resonance imaging (fMRI) to measure brain function of people engaged in economic decision-making. This proposal builds on previous work by the author examining the processes underlying human decision-making in a consequential social interaction with another person. These studies have found reliable, independent patterns of neural activity corresponding to affective and deliberative biases, and shown that subsequent decisions appear to be based on these different motives. In the present proposal, hypotheses generated in this previous study will be systematically tested. Experiments using fMRI and variants of Ultimatum and Trust Games will explore in greater depth the degree to which affective and deliberative processes influence decisions in both young and older populations. The field of neuroeconomics is growing rapidly as researchers from many different and disparate areas seek to understand the neural basis of human decision-making behavior. It allows the study of individuals in meaningful social interactions allied to sophisticated methodological and technological approaches enabling investigation at various levels, from behavioral responses to the neural activity that underlie them. This approach offers a valuable method by which to assess how decision-making operates across the lifespan, and this research can have immediate impact in terms of better understanding real-life decisions faced by elderly populations in a variety of important domains.